A conventional smoker assembly includes an cabinet containing one or more grill racks spaced vertically within the cabinet, a drip pan positioned below the grill for collecting food drippings, a water pan in the bottom of the cabinet, a heat source at the bottom of the cabinet, and a tray, placed adjacent the heat source, to hold the smoke generating material. Typical smoke generating material is wood and may include hickory, alder, and mesquite wood in a variety of forms including chips, briquettes, pellets, and saw dust. The heat source may include an electric heating element, a gas-fired burner, or combustible materials such as charcoal.
Smokers for slowly cooking food while imparting a smoke flavor to the food are illustrated, for example, in U.S. Pat. Nos. 7,426,885; 7,703,389; 5,713,267; 4,417,748; 4,309,938; 4,020,322; and 3,776,127. In addition, smokers that are designed as an added feature to a grill assembly are disclosed in U.S. Pat. Nos. 5,891,498; 5,718,165; 5,167,183; and 4,770,157. In addition, the prior art discloses a variety of apparatus for generating smoke and conveying the smoke to the food being smoked including U.S. Pat. Nos. 4,321,857; 6,209,533; and 5,138,939.
The smoking process is generally carried out at low to moderate temperatures over an extended period of time. For example, the internal temperature of the smoker is generally about 220° F.-230° F. At such temperatures, the smoking process generally takes about six hours. One smoking method, the 3-2-1 method, is often employed to smoke meat. For the first three hours, the meat is left uncovered on the smoker's grill rack so that the meat is surrounded by the smoke and thereby absorbs the smoke flavor from the heated wood chips. For the next two hours, the meat is wrapped in aluminum foil in order to steam and tenderize the meat. For the last hour, the meat is again left uncovered. The smoking process may also include basting the meat as the juices from the meat are caught in the drip pan and reapplied to the meat to keep the meat moist. In addition, the juices caught in the drip pan vaporize to maintain a moist atmosphere within the smoker cabinet thereby keeping the meat hydrated. The water pan also holds water or other flavor imparting liquids which, in conjunction with the heat source, add moisture to the atmosphere inside the smoker.
During the smoking a process, the internal temperature of the meat or other food product slowly rises, as a result of the heat created by the heat source at the bottom of the smoker, until the internal temperature of the meat reaches at least a safe level for consumption or to a higher level to suit the taste of the user.
Maintaining a constant set temperature in a smoker is important to ensure consistent results during the extended smoking process. Maintaining a constant temperature is affected by several factors including changes in atmospheric conditions outside of the smoker such as the presence of wind or rain, the temperature variation created by the introduction of the meat into the smoker, and the opening and closing of the door of the smoker to baste the meat, add wood chips, or check on the progress of the smoking process.
For electrically heated smokers, internal temperature of the smoker is controlled by an electric thermostat. The electric thermostat can react quickly to changes in internal temperature to maintain an essentially constant internal temperature.
For gas-fired smokers, controlling the internal temperature within a narrow range of variation is more difficult. Several considerations are present when controlling the internal temperature of a gas-fired smoker. The control system for a gas-fired smoker must react quickly to changes in internal temperature to maintain a relatively constant temperature while conserving gas, particularly when the smoker is used at a remote location.